1,091 research outputs found
CFD modelling of wind flow over complex and rough terrain
A model has been developed using the general-purpose Navier-Stokes solver CFX4 to
simulate Atmospheric Boundary Layer flow over complex terrain. This model has
been validated against the measured data from the Askervein Hill experiment, and has
been shown to perform well. The CFD model is also compared to the WAsP linear
model of wind flow over topography, and a significant improvement is noted for flow
over complex topography. Boundary conditions, gridding issues and sensitivity to
other solver parameters have all been investigated.
An advanced roughness model has been developed to simulate flow over forest
canopies, using a resistive body force within the canopy volume. The model is
validated against measured data for simple 2D cases, and for a complex 3D case over
real topography. The model is shown to give a more physically realistic profile for the
wind speed in and just above forest canopies than the standard roughness length
model used in most CFD simulations.
An automated methodology for setting up CFD simulations using the models
described has been developed. A custom pre-processing package to implement this
has been written, to enable the use of the CFD methodology in a commercial
environment
Evidence-based Management and Leadership
Organizations can be led and managed in many different ways and there is no shortage of perspectives, models, and frameworks for thinking about how such tasks can be accomplished. This chapter focuses on one such perspective: evidence-based management (EBMgt). At its core is the idea that when managers and organizations make decisions, evidence of various types should be collected, critically appraised, and taken into account. Put this way, EBMgt does not appear to be either new or radical. However, as we shall go on to discuss, recent attempts to elaborate and flesh out this idea show that while some of its core principles are unremarkable, actually doing EBMgt presents major challenges, threats, and opportunities. Far from being business as usual, using evidence seriously and systematically appears to represent a significant departure from what organizations typically do.
This chapter starts with an account of the origins of the idea of evidence-based practice in other fields and how it has been adapted in the development of EBMgt. It then looks at the sometimes controversial notion of leadership and what we know about what managers and leaders do. We then consider the extent to which leaders, managers, and organizations are evidence-based in their approach to managing organizations and what can be done to further develop this approach. Finally, we discuss some of the challenges that managing in an evidence-based way present to leaders and to more traditional ways of thinking about what leadership entails
Protocol for a longitudinal qualitative interview study: maintaining psychological well-being in advanced cancer - what can we learn from patients' and carers' own coping strategies?
IntroductionPeople with advanced cancer and their carers experience stress and uncertainty which affects the quality of life and physical and mental health. This study aims to understand how patients and carers recover or maintain psychological well-being by exploring the strategies employed to self-manage stress and uncertainty.Methods and analysisA longitudinal qualitative interview approach with 30 patients with advanced cancer and 30 associated family or informal carers allows the exploration of contexts, mechanisms and outcomes at an individual level. Two interviews, 4â12?weeks apart, will not only enable the exploration of individualsâ evolving coping strategies in response to changing contexts but also how patientsâ and carersâ strategies inter-relate. Patient and Carer focus groups will then consider how the findings may be used in developing an intervention. Recruiting through two major tertiary cancer centres in the North West and using deliberately broad and inclusive criteria will enable the sample to capture demographic and experiential breadth.Ethics and disseminationThe research team will draw on their considerable experience to ensure that the study is sensitive to a patient and carer group, which may be considered vulnerable but still values being able to contribute its views. Public and patient involvement (PPI) is integral to the design and is evidenced by: a research advisory group incorporating patient and carers, prestudy consultations with the PPI group at one of the study sites and a user as the named applicant. The study team will use multiple methods to disseminate the findings to clinical, policy and academic audiences. A key element will be engaging health professionals in patient and carer ideas for promoting self-management of psychological well-being. The study has ethical approval from the North West Research Ethics Committee and the appropriate NHS governance clearance.RegistrationNational Institute for Health Research (NIHR) Clinical Studies Portfolio, UK Clinical Research Network (UKCRN) Study number 11725
Sleep Profiles of Elite Swimmers During Different Training Phases
This study aims to describe the sleeping patterns during different training phases in competitive swimmers. Twelve national- and international-level swimmers (3 females and 9 males) were monitored during 4 different phases, consisting of a preparation training phase, a taper phase, a competition phase, and a rest phase. Sleep parameters were assessed using wrist activity monitors and self-reported sleep diaries. There was a moderately higher (d = 0.70â1.00) sleep onset latency during the competition phase compared with taper, train, and rest phases. Trivial to small differences were observed for total sleep time between phases (d = 0.05â0.40). Sleep efficiency was moderately higher (d = 0.60â0.75) in the training and taper phases compared with competition and rest. Restfulness and fragmentation index (FI) were lowest in the rest with differences between phases being small (d = 0.43â0.51) for restfulness and small to moderate (d = 0.43â0.62) for FI. Time in and out of bed was very largely later (d = 1.96â2.34) in rest compared with the other phases. Total nap time was moderately lower in rest (d = 1.13â1.18) compared with the training and competition phases, whereas there was a small difference (d = 0.46) compared with taper. To conclude, while there were trivial to small differences in sleep quantity between phases, there are small to moderate differences in other sleep parameters. Specifically, sleep onset latency was higher during the competition phase. In addition, this study highlights the substantial between-individual variations in sleep responses during different training phases
Estimating the potential yield of small building-mounted wind turbines
The wind profile in the urban boundary layer is described as following a logarithmic curve above the mean building height and an exponential curve below it. By considering the urban landscape to be an array of cubes, a method is described for calculating the surface roughness length and displacement height of this profile. Firstly, a computational fluid dynamics (CFD) model employing a k-Ï” turbulence model is used to simulate the flow around a cube. The results of this simulation are compared with wind tunnel measurements in order to validate the code. Then, the CFD model is used to simulate the wind flow around a simple pitched-roof building, using a semi-logarithmic inflow profile. An array of similar pitched-roof houses is modelled using CFD to determine the flow characteristics within an urban area. Mean wind speeds at potential turbine mounting points are studied, and optimum mounting points are identified for different prevailing wind directions. A methodology is proposed for estimating the energy yield of a building-mounted turbine from simple information such as wind atlas wind speed and building density. The energy yield of a small turbine on a hypothetical house in west London is estimated. The energy yield is shown to be very low, particularly if the turbine is mounted below rooftop height. It should be stressed that the complexity of modelling such urban environments using such a computational model has limitations and results can only be considered approximate, but nonetheless, gives an indication of expected yields within the built environment
A hypoenergetic diet with decreased protein intake does not reduce lean body mass in trained females
Purpose Increasing protein intake during energy restriction (ER) attenuates lean body mass (LBM) loss in trained males. However, whether this relationship exists in trained females is unknown. This study examined the impact of higher compared to lower protein intakes (35% versus 15% of energy intake) on body composition in trained females during 2 weeks of severe ER. Methods Eighteen well-trained females completed a 1-week energy balanced diet (HD100), followed by a 2-week hypoenergetic (40% ER) diet (HD60). During HD60, participants consumed either a high protein (HP; 35% protein, 15% fat) or lower protein (CON; 15% protein, 35% fat) diet. Body composition, peak power, leg strength, sprint time, and anaerobic endurance were assessed at baseline, pre-HD60, and post-HD60. Results Absolute protein intake was reduced during HD60 in the CON group (from 1.6 to 0.9 g·d·kgBMâ1) and maintained in the HP group (~â1.7 g·d·kgBMâ1). CON and HP groups decreased body mass equally during HD60 (â 1.0â±â1.1 kg; pâ=â0.026 and â 1.1â±â0.7 kg; pâ=â0.002, respectively) and maintained LBM. There were no interactions between time point and dietary condition on exercise performance. Conclusion The preservation of LBM during HD60, irrespective of whether absolute protein intake is maintained or reduced, contrasts with findings in trained males. In trained females, the relationship between absolute protein intake and LBM change during ER warrants further investigation. Future recommendations for protein intake during ER should be expressed relative to body mass, not total energy intake, in trained females
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Analysis of risk factors for catheter-related bloodstream infection in a parenteral nutrition population
Geological Appraisal of the Kish, Burford, Bray and Fraser Banks, Outer Dublin Bay Area
Geological mapping of the seabed and sub-seabed strata in an area comprising offshore banks and intervening sediments in outer Dublin Bay is presented. Bathymetric comparisons suggest that the offshore banks are quasi-stable over time probably maintaining their position due to the interaction between wave and current regimes. Seven acoustic seabed facies are defined on the basis of side-scan sonar characteristics reflecting differences in bedforms and bottom types. Sediment waves indicative of a mobile substrate are common both on and between banks. Maximum sandwave development occurs on bank flanks and outer limits. The effects of wave action on seabed morphology are clearly discernible in the structure and appearance of the bank crests. Grain-size data and bedform interpretations suggest a northerly sediment transport system with gravel dominant in the south of the area (Bray Bank) grading to sands in the north (Kish and Burford Banks). Sub-bottom profiling reveals a consistent upper unit overlying a hard reflector allowing unit thickness (isopachs) to be defined. No internal structures or âhardâ cores were revealed within banks. Two shipwrecks were also imaged.
This report forms part of a larger project "Reconnaissance Assessment of Coastal Seabed Sand and Gravel Resources" whose objective is to provide a comprehensive national survey, for the island of Ireland, of near-shore sand and gravel resources, to a water-depth of 50m, pertinent to all end-users e.g. aggregates industry, fisheries, local authorities, etc.
The aims of this larger project are to:
1. collate all known information (digital, documentary, archival and other sources) regarding the location and extent of the resources;
2. deliver this data as a national resource inventory using a GIS database in line with national standards;
3. ground-truth and extend the existing data coverage through additional surveys, where perceived data gaps or data ambiguities exist pertinent to national needs.
The resulting database (items 1 and 2) is comprised of three elements:
âąA MS Access database hosting comprehensive records of 63 datasets. Accessible from the metadata record for each dataset are:
âąAn archive of digital thematic data in ArcView shapefile format with associated legends, tables, and imagery;
âąA bibliographic database containing 406 bibliographic entries.
This report addresses Aim 3 of the larger project (above): âground-truth and extend the existing data coverage through additional surveys, where perceived data gaps or data ambiguities exist pertinent to national needsâ.Funder: Marine Institut
Adding Fish Oil to Whey Protein, Leucine and Carbohydrate Over a 6 Week Supplementation Period Attenuates Muscle Soreness Following Eccentric Exercise in Competitive Soccer Players
Soccer players often experience eccentric exercise-induced muscle damage given the physical demands of soccer match-play. Since long chain n-3 polyunsaturated fatty acids (n-3PUFA) enhance muscle sensitivity to protein supplementation, dietary supplementation with a combination of fish oil-derived n-3PUFA, protein, and carbohydrate may promote exercise recovery. This study examined the influence of adding n-3PUFA to a whey protein, leucine, and carbohydrate containing beverage over a six-week supplementation period on physiological markers of recovery measured over three days following eccentric exercise. Competitive soccer players were assigned to one of three conditions (2 à 200 mL): a fish oil supplement beverage (FO; n = 10) that contained n-3PUFA (1100 mg DHA/EPA - approximately 550 mg DHA, 550 mg EPA), whey protein (15 g), leucine (1.8 g), and carbohydrate (20 g); a protein supplement beverage (PRO; n = 10) that contained whey protein (15 g), leucine (1.8 g), and carbohydrate (20 g); and a carbohydrate supplement beverage (CHO; n = 10) that contained carbohydrate (24 g). Eccentric exercise consisted of unilateral knee extension/flexion contractions on both legs separately. Maximal force production was impaired by 22% during the 72-hour recovery period following eccentric exercise (p < 0.05). Muscle soreness, expressed as area under the curve (AUC) during 72-hour recovery, was less in FO (1948 ± 1091 mm à 72 h) than PRO (4640 ± 2654 mm à 72 h, p < 4 0.05) and CHO (4495 ± 1853 mm à 72 h, p = 0.10). Blood concentrations of creatine kinase, expressed as AUC, were ~60% lower in FO compared to CHO (p < 0.05) and tended to be lower (~39%, p = 0.07) than PRO. No differences in muscle function, soccer performance, or blood c-reactive protein concentrations were observed between groups. In conclusion, the addition of n-3PUFA to a beverage containing whey protein, leucine, and carbohydrate ameliorates the increase in muscle soreness and blood concentrations of creatine kinase following eccentric exercise in competitive soccer players
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